US6856748B1 - Interconnection enclosure having a connector port and preterminated optical connector - Google Patents

Abstract

An interconnection enclosure comprising at least one connector port operable for receiving a connector pair and a preterminated optical connector received in the at least one connector port, wherein the preterminated optical connector is adapted to be withdrawn from the exterior of the enclosure without entering the enclosure. The enclosure further comprising a tether means, a bend radius control means and a sealing means. An interconnection enclosure comprised of two halves held together by a fastening means, the enclosure defining an end wall and defining at least one connector port opening through the end wall for receiving a preterminated optical connector, the enclosure housing further defining an opening for receiving a distribution cable extending therethrough, wherein the preterminated optical connector is adapted to be withdrawn from the exterior of the enclosure without entering the enclosure.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to an enclosure for interconnecting preterminated optical fibers, and more specifically, to an enclosure having at least one connector port and at least one preterminated fiber optic connector that provides access to the preterminated connectors from the exterior of the enclosure.

2. Description of the Related Art

Optical fiber cable is used for a variety of applications including voice communications, data transmission and the like. As a result of the increase in demand, fiber optic networks typically include an ever-increasing number of access points in which one or more optical fibers are branched from a distribution cable. These access points provide an increase in the number of connections in a given area and may be used to supply “fiber-to-the-premises” (FTTP). Based on the increase in the number of access points, and based on the unique physical needs of the optical fibers themselves, an enclosure is needed for protecting, handling, connecting and maintaining the optical fibers and their respective connectors. The enclosure should provide protection of the access point, the branched fibers and the connectors from environmental and mechanical factors, such as weather and stress.

Branching a distribution cable may involve branching and/or splicing one or more optical fibers that make up the cable. Distribution cables may range in length from meter to kilometer lengths, and may comprise a plurality of access points located at predetermined positions along their length. Drop cables, typically smaller than distribution cables, may be routed from the distribution cable to predetermined locations, such as a “network interface device” (NID) or a “network access point” (NAP). In various conventional drop cable designs, a technician may be responsible for accessing and splicing specific optical fibers of a distribution cable in the field. This costly and time consuming process requires sending a technician to the site, removing a portion of the cable sheath at a predetermined location, locating the appropriate optical fibers, cutting the appropriate optical fibers, branching and/or splicing the optical fibers to a drop cable optical fiber and installing an enclosure. In addition, conventional designs typically include a splice tray mounted within the enclosure for handling the splice point and storing slack cable. Using these conventional designs, if it is desired to service or alter the splice point, or to branch an additional optical fiber at the same access point, the enclosure must be opened and entered.

Optical fibers that have been accessed from a distribution cable must be protected from mechanical stresses, such as bending and tensile forces. A minimum bend radius, such as about 1.50 inches, must be maintained in order to properly transmit light through the core of the optical fiber. Too great a tensile force applied to an optical fiber, such as that applied by the weight of a drop cable or environmental factor, may damage the drop cable, splice point, distribution cable and other branched optical fibers. Conventional enclosure design does not adequately provide for bend radius control and fiber travel limitation. More importantly, conventional enclosure design does not allow access to the optical fibers from the exterior of the enclosure, while still providing for bend radius and travel control. In optical fiber enclosures, it is often necessary to clean or service the connectors. To do this, it is necessary to remove some quantity of optical fiber length from the enclosure. If two much length is pulled, two problems may occur: The first is that the optical fiber within the enclosure may be pulled around a tight corner or bend, exceeding the bend radius of the fiber and causing damage. The second is that the fiber may be damaged while pushing it back into the enclosure. Conventional enclosure design requires that special care be taken to not exceed the minimum bend radius when opening an enclosure to access the optical fibers contained therein. Thus, conventional enclosure design requires that a field technician spend extra time and effort to ensure that the optical fiber integrity is not compromised during cleaning and servicing procedures.

What is desired is an enclosure that allows for damage-free fiber slack removal and replacement during connector cleaning and servicing. Further, what is desired is a manufactured preterminated optical fiber cable comprising a plurality of factory or field-installed enclosures located at predetermined positions along the cable length, wherein the enclosure architecture allows access to preterminated connectors from the exterior of the enclosure. What is further desired is an enclosure comprising at least one connector port that provides access to preconnectorized optical fibers, which will lead to rapid and low-cost drop cable installation. The enclosure should be capable of handling and protecting the optical fibers and their respective connectors, provide for bend radius control of the optical fibers and allow access to the connectors for cleaning and servicing from the exterior of the enclosure. Thus, there is a need in the art for an enclosure that eliminates the need for the field splicing of drop cables, and eliminates the need for a field technician to have to open and enter the interior of the enclosure to clean, service and gain access to preterminated connectors, which may disturb and damage the contents of the enclosure.

BRIEF SUMMARY OF THE INVENTION

To achieve the foregoing and other objects, and in accordance with the purpose of the present invention as embodied and broadly described herein, the present invention provides various embodiments of optical fiber interconnection enclosures having a connector port and preterminated connectors that may be withdrawn and reloaded from the exterior of the enclosure without entering the interior of the enclosure. In various embodiments, the present invention describes factory and field-installed interconnection enclosures. In various embodiments, the present invention also describes apparatus within the enclosure that prevent fiber over-travel while maintaining bend radius control, reducing the risk of damaging the optical fibers and their respective connectors during cleaning and servicing procedures. The enclosures described below may be used to handle and protect spliced/spliceless optical fibers that are preterminated at various predetermined positions along the length of a fiber optic cable.

In various embodiments, the present invention describes an interconnection enclosure comprising at least one connector port operable for receiving a connector pair and a preterminated connector received in the at least one connector port. The preterminated connector is accessed from the exterior of the enclosure without entering the enclosure, thus providing access to the ferrule and the connector for cleaning and servicing. In other embodiments, the enclosure further comprises a tether means within the enclosure housing operable for limiting an extension distance of the preterminated connectors exterior of the enclosure. In a further embodiment, the termination enclosure comprises a bend radius control means for handling and maintaining a minimum bend radius of the preterminated optical fibers within the enclosure housing. In still further embodiments, a sealing means, such as an invertable rubber boot, is operable for sealing the at least one connector port from the environment exterior of the enclosure when a preterminated connector is engaged with its respective connector port. The invertable rubber boot may further provide a tether function for the optical fibers.

In a still further embodiment, the present invention describes an interconnection enclosure comprised of two portions held together by a fastening means, the enclosure housing defining end walls and defining at least one connector port opening through at least one of the end walls for receiving a preterminated connector, the enclosure housing further defining an opening for receiving a distribution cable extending therethrough. The enclosure architecture allows for a preterminated connector branched from a distribution cable to be accessed from the exterior of the enclosure. The enclosure may further comprise a tether means within the enclosure operable for limiting an extension distance of the preterminated connector exterior of the enclosure, and a sealing means within the enclosure operable for sealing the at least one connector port when the preterminated connector is engaged with the connector port. The enclosure may further comprise a bend radius control means for maintaining a minimum bend radius of the optical fibers. The interconnection enclosure may be factory or field-installed.

In a still further embodiment, the present invention describes a preterminated fiber optic connection comprising an access point located at a predetermined position on a distribution cable, at least one optical fiber of the distribution cable accessed via the access point, a closure housing forming a cavity therein and defining a passage for the distribution cable extending therethrough, at least one connector port, a tethering means and a sealing means. The preterminated connector may be accessed from the exterior of the enclosure via the connector port without opening or entering the enclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the present invention are better understood when the following detailed description of the invention is read with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective view of an interconnection enclosure having at least one connector port in accordance with an exemplary embodiment of the present invention;

FIG. 2ais a perspective view of one half of an interconnection enclosure comprising a tether means and a direct terminated optical fiber having a preterminated connector in accordance with an exemplary embodiment of the present invention;

FIG. 2bis a perspective view of one half of an interconnection enclosure comprising a tether means and fusion-spliced optical fibers having preterminated connectors in accordance with an exemplary embodiment of the present invention;

FIG. 3ais a cross-sectional view of a preterminated connector, a connector port cover and a connector sealing means in a retraced position in accordance with an exemplary embodiment of the present invention;

FIG. 3bis a cross-sectional view of the preterminated connector and connector sealing means ofFIG. 3ain an extended position, wherein the connector port cover and the adapter sleeve are removed in accordance with an exemplary embodiment of: the present invention;

FIG. 4ais a perspective view of a tether means with bend radius control in a retracted position in accordance with an exemplary embodiment of the present invention;

FIG. 4bis a perspective view of the tether means with bend radius control ofFIG. 4ain an extended position in accordance with an exemplary embodiment of the present invention;

FIG. 5ais a perspective view of an assembled and retracted preterminated connection comprising an adapter sleeve, a sealing means and a tether means in accordance with an exemplary embodiment of the present invention;

FIG. 5bis a perspective view of the preterminated connection ofFIG. 5ain a disassembled and extended position in accordance with an exemplary embodiment of the present invention;

FIG. 6 is a perspective view of a bend radius control apparatus in accordance with an exemplary embodiment of the present invention; and

FIG. 7 is a perspective view of a preterminated connector and receptacle assembly in accordance with an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These exemplary embodiments are provided so that this disclosure will be both thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference numbers refer to like elements throughout the various drawings.

The present invention provides various embodiments of factory- and field-installed interconnection enclosures having at least one connector port through which preterminated optical connectors are accessible from the exterior of the enclosure without having to open or enter the enclosure. The various embodiments of the present invention may be applied in a “fiber-to-the-premises” (FTTP) termination system, or in any other termination system in which is it desired to access optical fibers of a distribution cable. Throughout the specification, the term “enclosure” is intended to included all types of enclosures including, but not limited to, aerial closures, splice closures, buried enclosures and wall-mounted enclosures. Throughout the specification, the term “distribution cable” is intended to include all types of optical fiber cables comprising a plurality of optical fibers within a sheath including, but not limited to loose tube, tight buffered and monotube designs. Preconnectorized drop cables may be connected to, and disconnected from, the preterminated connectors at the connector ports from the exterior of the enclosure, thus eliminating the need for opening or entering the enclosure to access the preterminated connectors. Further, the present invention eliminates the need for fusion and mechanical splicing in the field for the purpose of branching optical fibers along the length of a distribution cable.

FIG. 1 shows an example of anenclosure20 comprises two substantiallysymmetrical halves22,24 held together by a fastening means including, but not limited to, screws, bolts, clamps, hooks or latches received throughopenings21. Although not shown, a rubber gasket operable for providing a weatherproof seal may be disposed between the twohalves22,24 in a groove or channel defined by the twohalves22,24. Theexemplary enclosure20 has a generally cylindrical shape and defines acavity26 therein, hereinafter referred to as the “interior” of theenclosure20. Although shown having a cylindrical shape, the enclosure may be of any size, shape or number of portions suitable for enclosing the access point and exposed buffer tubes. The region outside of theenclosure20 is hereinafter referred to as the “exterior” of theenclosure20. Theenclosure20 defines horizontal cable pathway features28 that extend from the end walls of theenclosure20 in the axial direction. Adistribution cable30 passes through and is routed by the horizontal cable pathway features28. Theenclosure20 further defines at least oneconnector port32 that opens through at least oneend wall34 of theenclosure20. Although theenclosure20 is shown having 4connector ports32 opening through only one housing or endwall34, it is envisioned that any number ofconnector ports32 may open through either or both end walls. Theconnector ports32 are shown occupied by connector port covers36.

Although not shown, when theenclosure20 is installed and the twohalves22,24 held together, a heat recoverable material, such as a heat shrink, may be placed over a portion of the enclosure horizontal cable pathway features28 in order to provide a weather-proof seal at the locations where thedistribution cable30 enters and exits theenclosure20. The heat shrink may further function to hold the twohalves22,24 together and maintain the position of theenclosure20 over an access point along the cable length. The hear shrink should substantially cover the horizontal cablepathway defining features28 and a portion of thedistribution cable30. The “access point” is hereinafter defined as the point along the cable length at which the cable sheath has been removed to expose the underlying buffer tubes, thus permitting access to the buffer tubes encasing the optical fibers. The cable sheath may be removed by ring cutting or by any technique known to those skilled in the art.

Theenclosure20 may be factory or field-installed. In the case of field-installed applications, thedistribution cable30 may have a plurality of factory preterminated connectors encased by a heatrecoverable material38, such as a heat shrink material. For field installation of the enclosure, the heat shrink material may be removed to expose the access point along the cable length and the plurality of preterminated connectors. Theenclosure20 may then be installed over the access point and the preterminated connectors connected to theirrespective connector ports32. In factory-installed applications, adistribution cable30 may have a plurality of enclosures attached at predetermined locations along the cable length with the preterminated connectors already attached to theirrespective connector ports32. In both applications, the preterminated connectors may be directly terminated or spliced, which is discussed below in greater detail. In both applications, thedistribution cable30, with or without theenclosures20 attached at predetermined locations, may be rolled onto a reel for distribution.

Still referring toFIG. 1, the interior of theenclosure20 is of a volume sufficient to house and handle thedistribution cable30, the accessed optical fibers, the preterminated connectors, a bend radius control means, optical fiber slack and splice holders that may be used with fusion splicing applications. Preferably, theenclosure20 has a diameter just large enough to enclose the distribution cable, bend radius control means, optical fiber slack and sealing means. It is preferred that theenclosure20 be long enough to completely encase the access point. The access point is preferably from about 1 to about 15 inches in length, or long enough to access at least 1 inch of optical fiber.

Referring toFIG. 2a, a factory-installedenclosure20 is shown having a direct-terminatedoptical fiber44 having apreterminated connector40 and a tether means42 for limiting the travel of theconnector40 exterior of theenclosure20. The tether means42 not only limits the amount offiber44 that can be removed from theenclosure20, but facilitates its replacement at the end of the cleaning or servicing operation. This may require an elastic tether with a tensile element operable for preventing fiber extension beyond a predetermined point. The tether means42 requires a structure inside theenclosure20 that will allow the desired amount offiber44 to be withdrawn and reloaded without damage. The most simple tether embodiment may comprise an enclosure housing defining a cavity capable of containing thefiber44 at both installed and extended positions. In this embodiment, thefiber44 may be pulled from theenclosure20 using minimal force, the connector assembly cleaned and serviced, then the tether pulls the connector assembly back into the housing. A more complicated approach may comprise a spring or elastomer element. In current practice, one relies on the skill of the field technician to not pull theconnector40 out of theenclosure20 to a position where thefiber44 is damaged. In a similar fashion, using current enclosure design, one also relies on the skill of the technician to get the fiber slack back into theenclosure20 without damaging thefiber44 or the contents of theenclosure20.

The tether means42 limits the travel of thepreterminated connector40 exterior of theenclosure20. InFIG. 2a, in one embodiment, ahose clamp48 andtether cord50 secured to both thedistribution cable30 and thepreterminated connector40 are the tether means42. Thetether cord50 may be an inelastic or elastic material with a predetermined maximum extension distance. The extension distance of the tether means42 determines the extension distance of thepreterminated connector40 exterior of theenclosure20. In the case of an elastic tether means42, the elasticity may aid in the reloading of thepreterminated connector40 after it has been withdrawn from theenclosure interior26. The extension distance of thepreterminated connector40 from theconnector port32 is preferably from about 1 to about 6 inches, and should not be less than about 1 inch. The extension distance should be adequate to allow access to the ferrule of theconnector40 for cleaning, polishing and replacing. Thehose clamp48 secured around the distribution cable sheath provides an adequately strong anchoring point for thetether cord50. It is preferred that thehose clamp48 be secured over the cable sheath so as not to damage the exposed buffer tubes. In an alternative embodiment, the tether means42 may be secured at one end to theoptical fiber44, and secured at the other end to an interior surface of the enclosure housing.

Theenclosure20 is shown having a bend radius control means46 secured to one half of the enclosure housing. The bend radius control means46 is operable for maintaining a minimum bend radius, preferably greater than about 1.5 inches, of theoptical fibers44. The bend radius control means46 shown inFIG. 2ahas a cylindrical shape and may define grooves or channels on its outer surface which guides theoptical fibers44 around the outer surface. Thepreterminated connector40 is shown connected to one of theconnector ports32 that open through theend wall34 of theenclosure20. Although not shown, a drop cable may be connected to the exterior side of theconnector port32, thus forming a preterminated connection. The drop cables do not enter theenclosure20. Theconnector port32 provides an adequately strong anchoring point for supporting the weight of the drop cable. The force applied to theconnector port32 from the weight of the drop cable is transferred from theconnector port32 to theenclosure20 housing, which is secured by thedistribution cable30 and the heat shrink material secured around the pathway features28 of theenclosure20. The force from the weight of the drop cable is not transferred to thepreterminated connector40 of theoptical fiber44.

Referring toFIG. 2b, a factory-installedenclosure20 is shown having factory fusion-splicedoptical fibers44 having preterminatedconnectors40 and a tether means42 for limiting the travel of theconnectors40 exterior of theenclosure20. Thedistribution cable30 is shown having theoptical fibers44 fusion-spliced at a low-profile access point. Although 4preterminated connectors40 are shown, only onepreterminated connector40 is shown connected to theconnector port32 that opens through theend wall34 of theenclosure20. Although not shown, a drop cable may be connected to the exterior side of theconnector port32, thus forming a preterminated connection. Again, the drop cables attach on the exterior of theenclosure20 and do not enter theenclosure20. Theconnector port32 provides an adequately strong anchoring point for supporting the weight of the drop cable. The tether means42 limits the travel of thepreterminated connectors40 exterior of theenclosure20.

The exemplary fusion-splice embodiment shown inFIG. 2bwas prepared by the method described below. The fusion splice and method of producing the splice are not intended to limit the invention, but serve as one example in which the distribution cable may be accessed and factory preterminated. Thedistribution cable30 shown is a single-mode 2-72 fiber cable with 6 positions for the helically s-z stranded buffer tubes. This exemplary cable comprises 12optical fibers44 per tube. The buffer tubes may be accessed by removing a substantial portion of the outer sheath encased by theenclosure30, as described above. A predeterminedbranched buffer tube46 may be accessed by ring cutting opposing ends and running the length of the tube with a blade that resides in a tool referred to as an “optical fiber access tool” (“OFAT”). The cut buffer portion may then be removed, exposing the 12optical fibers44. Eachoptical fiber44 may be comprised of a core, cladding and a coating, having sizes of about 8 microns, 125 microns and 250 microns in diameter, respectively.

The exemplary splice shown illustrates the connectorization of 4optical fibers44 that connect to 4connector ports32. The 8 remaining unusedoptical fibers44 may be removed. Theoptical fibers44 may be cleaned and prepared for splicing. Eachoptical fiber44 may be spliced together with a pre-connectorized “pigtail” into 4 pairs using a fusion splicer. A reinforcedsplice protector52 for splice protection may be slid into the correct position, centered over the spliced intersection and shrunk permanently into place. The splice points may be held in place using asplice holder54, such as a rubber or plastic material defining channels or grooves operable for holding asplice protector52 in place. Thesplice holder54 may be secured to an interior surface of the enclosure housing or to thedistribution cable30.

Still referring toFIG. 2b, thetether cord50 may be fixably attached to theoptical fiber44 and secured to either thedistribution cable30 or to an interior surface of theenclosure20. The position of thehose clamp48 and the length of thetether cord50 determine the maximum extension distance of theconnectors40 exterior of theenclosure20. The extension distance of thepreterminated connector40 from theconnector port32 is preferably from about 1 to about 6 inches, and should not be less than about 1 inch. The extension distance should be adequate to allow access to the ferrule of theconnector40 for cleaning, polishing, repairing and replacing. Thehose clamp48 tethered to either thedistribution cable30 or to an interior surface of theenclosure20 provides an adequately strong anchoring point for theconnectors40 of theoptical fibers44.

Referring toFIG. 3a, a sealing means, such as aninvertable sealing boot56 may simultaneously act to seal the backside of theconnector port32 and provide over-travel prevention capability. The sealingboot56 inFIG. 3ais shown in a retracted position in which thepreterminated connector40 is disposed in theinterior26 of theenclosure20. The length of the sealingboot56 determines anextension distance58 of theconnector40 exterior of theenclosure30. The sealing function of the sealingboot56 protects the preterminated connection while allowing the rest of theenclosure20 to remain unsealed. By using individual boot seals for each preterminated connection, it is insured that the sealing ofother connectors40 within theenclosure20 are not affected while one connection is attended to. The sealingboot56 may be secured to its respectiveoptical fiber44 using a heat shrink, clamp, strap or other fastening mechanism. The sealingboot56 may be connected at its other end to aconnector port receptacle60 using a clamp, strap, interference fit or other fastening mechanism. When withdrawing theconnector40 from the interior of theenclosure20, the sealingboot56 inverts upon itself as fiber slack is pulled from theenclosure20. As theconnector40 is reloaded into the interior of theenclosure20, the sealingboot56 reverts back to its original shape. The sealingboot56 should maintain its elastic properties over a wide temperature range, such as from about −40° C. to about 85° C.

Still referring toFIG. 3a, thepreterminated connector40 is connected to anadapter sleeve62 that resides within thereceptacle60 secured to theconnector port32. Theadapter sleeve62 may be biased in the direction of theend wall34 of theenclosure20 and brings the ferrule of thepreterminated connector40 into contact with the ferrule of an attached drop cable. Areceptacle cap64 fits securely within thereceptacle60 and is operable for holding theadapter sleeve62 within thereceptacle60. Thereceptacle cap64 preferably engages thereceptacle60 using a snap-fit design, but may comprise a screw-fit, bayonet-fit or any other interference-fit design. Although not shown, a removable connector port cover36 occupies theconnector port40 when a drop cable is not attached to the exterior surface of theadapter sleeve62. The connector port cover36 may be secured using a snap-fit, screw-fit, bayonet-fit or any other interference-fit design.

Referring toFIG. 3b, the sealingboot56 is shown in an extended position in which thepreterminated connector40 is exterior of theenclosure20. In this illustration, theconnector port cover36, thereceptacle cap64 and theadapter sleeve62 have been removed and are not shown. The sealingboot56 simultaneously acts to seal the backside of theconnector port32 and provides the over-travel prevention capability. A drop cable comprising asimilar sealing boot56 may be connected to the exterior side of theadapter sleeve62 to seal the preterminated connection. Thepreterminated connector40 is exterior of the enclosure20 a distance determined by the length of the sealingboot extension distance58. The extension distance provides access to theconnector40 from the exterior of theenclosure20 without having to enter theenclosure20. As stated above, the sealingboot56 is secured to its respectiveoptical fiber44 and theconnector port receptacle60. The sealingboot56 will revert to its retracted configuration when thepreterminated connector40 is reloaded into theenclosure20. Although the sealingboot56 is shown extended beyond the exterior surface of theconnector port32, in an alternative embodiment, when inverted the sealingboot56 may not be extended beyond the exterior surface so as not to damage the sealingboot56 or pull it off of thereceptacle60.

Referring toFIG. 4a, another embodiment of a tether means42 and a bend radius control means46 is shown for accessing apreterminated connector40 from the exterior of anenclosure20. Although not shown, the sealing means illustrated inFIGS. 3aand3bmay be used with the tether and bend radius control design ofFIGS. 4aand4b. The sealingboot56 may simultaneously act to seal the backside of theconnector port32 and provideoptical fiber44 over-travel prevention capability. In an alternative embodiment, a hardened connector with a sealing means, such as an o-ring, may be disposed between the exterior surface of the connector and the interior surface of theadapter sleeve62. To seal the preterminated connection on the exterior side of theadapter sleeve62, a sealing means, such as an o-ring, may be disposed between the exterior surface of theadapter sleeve62 and a connector of a drop cable. The sealingboot56 may be used alone or in combination with the o-ring sealing means.

Thepreterminated connector40 inFIG. 4ais shown in a retracted position within theinterior26 of theenclosure20. A spring-loaded tether means42 may be used to provide tether and bend radius control functions. In addition, in tightly constrained spaces the spring may function as a means of pulling theconnector40 back into theenclosure20 in the desired orientation. Inenclosures20 having a large interior, the means for pulling theconnector40 back into theenclosure20 may not be needed. Anoptical fiber44 may be routed by africtionless groove66 defined by a firstsemicircular portion68 of the tether means42. One or morehelical springs70 disposed between thefirst portion68 and asecond portion72 of the tether means42 may be operable for providing tension between the two portions. Referring toFIG. 4b, when theconnector40 is withdrawn from the interior of theenclosure30, thesprings70 compress and theoptical fiber44 slides along the outer surface of thefirst portion68. Referring toFIG. 4a, when theconnector40 is reloaded into the interior of theenclosure20, the springs provide a tension force for reloading the optical fiber slack. The length of thesprings70 and the amount that they can be compressed determines theextension distance58 of theconnector40 exterior of theenclosure30. The sealingboot56, if used, may also determine theextension distance58. The tether means42 may be secured to thedistribution cable30 or to an interior surface of theenclosure20 using any fastening means.

FIG. 5ashows an assembled view of another embodiment of a tether and bend radius control means42 for accessing apreterminated connector40 from the exterior of anenclosure20. Anadapter sleeve62 disposed within theconnector port32 is connected to both thepreterminated connector40 and adrop cable74. Sealing boots56 are removably attached to theoptical fibers44 and theend wall34 of the enclosure on both thepreterminated connector40 side and on the drop cable side to seal the preterminated connection. The sealing boots56 may be attached to theend wall34 using a fastening means including, but not limited to, screws76 or snaps. As stated above, the sealingboot56 may simultaneously act to seal theconnector port32 and provideoptical fiber44 over-travel prevention capability. In an alternative embodiment, an additional sealing means, such as an o-ring, may be disposed between the exterior surface of the connector and the interior surface of theadapter sleeve62. To further seal the preterminated connection on the exterior side of theadapter sleeve62, a sealing means, such as an o-ring, may be disposed between the exterior surface of theadapter sleeve62 and the connector of the drop cable. Thepreterminated connector40 inFIG. 5ais shown in a retracted position within theinterior26 of theenclosure20. A spring-loaded tether means42 may be used to provide tether, bend radius control and connector retraction functions. Theoptical fiber44 travels around the exterior of thecoil spring70 when slack is withdrawn or reloaded. Thespring70 is fixed to an interior surface of theenclosure20 or to thedistribution cable30.

FIG. 5bshows the preterminated connection ofFIG. 5ain a disassembled and extended position. When theconnector40 is withdrawn from the interior of theenclosure30, thespring70 compresses and theoptical fiber44 slides along the outer surface of thespring70. In order to withdraw theconnector40, thedrop cable74 and theadapter sleeve62 are detached from theend wall34. In one example, theadapter sleeve62 may be attached to the exterior surface of theend wall34 using screws. The drop cable andpreterminated connectors40 may be accessed for cleaning by inverting the sealingboot56 upon itself and exposing the connectors. The length of thespring70 and the amount that it can be coiled determines theextension distance58 of theconnector40 exterior of theenclosure30. The sealingboot56 may also determine theextension distance58. Thespring70 should not compress to a diameter smaller than the minimum bend radius of theoptical fiber44.

Referring toFIG. 6, an alternative embodiment of an apparatus for bend radius control is shown. A “mushroom” shapedapparatus78 may be secured around thedistribution cable30 at the predetermined branch position along the cable length. The branchedoptical fibers44 are routed over the surface of the cap-portion to theirrespective connector ports32. The bend-limiting apparatus may be factory or field-installed. Further, the apparatus may comprise aspring70 disposed between theapparatus shaft80 and thedistribution cable30, and fixed to the distribution cable. Thespring70 provides a tether and a slack reloading function. Theshaft80 may define grooves operable for channeling theoptical fibers44 along thedistribution cable30.

FIG. 7 shows a specific embodiment of a receptacle assembly that resides within theconnector port32. Thereceptacle60 is fixed to theend wall34 of theenclosure20. Theadapter sleeve62 resides within thereceptacle60 and is biased in the direction of theend wall34 of theenclosure20. Theadapter sleeve62 and thepreterminated connector40 are accessible from the exterior of theenclosure20. Theadapter sleeve62 is held in place by thereceptacle cap64 that fits securely within thereceptacle60. Thereceptacle cap64 preferably engages thereceptacle60 using a snap-fit design, but may comprise a screw-fit, bayonet-fit or any other interference-fit design. The removable connector port cover36 occupies theconnector port40 when a drop cable is not attached to the exterior surface of theadapter sleeve62. The connector port cover36 may be secured using a snap-fit, screw-fit, bayonet-fit or any other interference-fit design. The specific embodiment shown inFIG. 7 is just one example of an assembly for connecting a preterminated connector pair, it is envisioned that other assemblies may perform similar functions.

The foregoing is a description of various embodiments of the invention that are given here by way of example only. Although theoptical fiber enclosures20 and related apparatus have been described with reference to preferred embodiments and examples thereof, other embodiments and examples may perform similar functions and/or achieve similar results. All such equivalent embodiments and examples are within the spirit and scope of the present invention and are intended to be covered by the following claims.

Claims (16)

1. An interconnection enclosure comprising at least one housing wall separating an interior of the enclosure from an exterior of the enclosure, the housing wall having an opening therethrough, the enclosure comprising:

at least one connector port positioned within the opening of the housing wall and operable for receiving a preterminated optical connector from the interior of the enclosure;

the preterminated optical connector attached to an optical fiber that is optically connected to a distribution cable; and a tether means within the interior of the enclosure;

wherein the preterminated optical connector is adapted to be withdrawn from the enclosure without entering the enclosure and the tether is operable for limiting an extension distance of the preterminated optical connector withdrawn from the enclosure.

2. The interconnection enclosure ofclaim 1, further comprising a bend radius control means for maintaining a minimum bend radius of the optical fiber.

3. The interconnection enclosure ofclaim 1, further comprising a sealing means operable for sealing the at least one connector port.

4. The interconnection enclosure ofclaim 3, wherein the sealing means is an invertable rubber boot operable for providing a sealing function and a tether function.

5. The interconnection enclosure ofclaim 1, wherein the connector port comprises a receptacle fixably attached to the housing wall, a removable receptacle cap positioned within the receptacle, a removable receptacle cap cover and a removable adapter sleeve, wherein the adapter sleeve is removable from the connector port through the housing wall of the enclosure without entering the enclosure.

6. The interconnection enclosure ofclaim 1, wherein the enclosure is operable for enclosing at least one of direct-terminated optical fibers and fusion-spliced optical fibers.

7. The interconnection enclosure ofclaim 1, wherein the enclosure is factory-installed or field-installed.

8. An interconnection enclosure, comprising:

an enclosure housing comprising two housing halves held together by a fastening means, the enclosure housing defining an end wall and defining at least one connector port opening through the end wall for receiving a preterminated optical connector, the enclosure housing further defining an opening for receiving a distribution cable extending therethrough; and a tether means within the enclosure operable for limiting an extension distance of the preterminated optical connector exterior of the enclosure;

wherein the preterminated optical connector is adapted to be withdrawn from the enclosure without entering the enclosure.

9. The interconnection enclosure ofclaim 8, further comprising a sealing means within the enclosure operable for sealing the at least one connector port.

10. The interconnection enclosure ofclaim 9, wherein the sealing means is an invertable rubber boot operable for providing a sealing function and a tether function.

11. The interconnection enclosure ofclaim 8, further comprising a bend radius control means for maintaining a minimum bend radius of preterminated optical fibers.

12. The interconnection enclosure ofclaim 8, wherein the connector port comprises a receptacle fixably attached to the enclosure end wall, a removable receptacle cap within the receptacle, a removable receptacle cap cover and a removable adapter sleeve, wherein the adapter sleeve is removable from the receptacle from the exterior of the enclosure without entering the enclosure.

13. The interconnection enclosure ofclaim 8, wherein the enclosure is factory-installed or field-installed.

14. A preterminated fiber optic connection, comprising:

an access point located at a predetermined position on a distribution cable comprising a plurality of optical fibers;

at least one optical fiber of the distribution cable branched from the distribution cable at the access point;

a preterminated optical connector attached to the at least one optical fiber;

an enclosure forming a cavity therein and defining a passage for the distribution cable extending therethrough, the enclosure further defining at least one connector port opening through at least one end wall of the enclosure;

a tethering means; and

a bend radius control means;

wherein the preterminated optical connector is adapted to be withdrawn from the exterior of the enclosure without entering the enclosure.

15. The preterminated connection ofclaim 14, further comprising a sealing means within the enclosure operable for sealing the at least one connector port.

16. The preterminated connection ofclaim 15, wherein the sealing means is an invertable rubber boot.

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